For the provision of color-changing cosmetic agents, especially for the skin or keratin-containing fibers such as for example human hair, the person skilled in the art is aware of diverse dyeing systems according to the requirements of the dyeing. The so-called oxidation dyes are used for long-lasting, intensive colorations with corresponding authentic characteristics. Dyes of this type usually comprise oxidation dye precursors, so-called developer components and coupler components which together under the influence of oxidizing agents or of atmospheric oxygen form the actual dyes. The oxidation dyes are distinguished by outstanding, long-lasting coloration results. In addition to dyeing, many consumers quite specifically wish to lighten or blond their own hair color. For this, the natural or synthetic dyes used to color the fibers are removed, mostly oxidatively, by employing appropriate oxidizing agents, such as for example hydrogen peroxide. For temporary colorations, usually colorants or toners are used that comprise so-called substantive dyes as the coloring component. These can likewise be incorporated along with oxidizing agents in lightening dyes.
In order to develop an optimal dyeing power, oxidative dyes generally need an alkaline pH for dyeing, especially between pH 9.0 and pH 11.5. For reasons of stability, oxidative dyes are usually only prepared directly prior to their application by blending a color-changing preparation and an oxidizing agent preparation. In order to stabilize oxidation dye precursors, the color-changing preparation usually has an alkaline pH, and in order to stabilize the oxidizing agent, the oxidizing agent preparation has an acidic pH, whereas the application mixture should have an alkaline pH in order to enable a good penetration of the dye precursor and the oxidizing agent into the keratinic fibers.
Moreover, the application period for attractive coloring results is usually between 10 and 60 minutes. The ready-for-use color-changing agent therefore needs to be formulated and packaged such that firstly, the colorant can be well dispersed onto the keratinic fibers being dyed and, secondly, however, that it remains in the fibers being dyed during the contact time. For this it is advantageous if the colorant has a certain viscosity that indeed enables the agent to be applied, but also allows the agent to remain at the place of application. This viscosity can be adjusted by polymeric thickeners in the ready-for-use colorant, wherein this thickener can be comprised in the color-changing preparation or in the oxidizing agent preparation.
In order to enable a good mixing of the color-changing preparation and oxidizing agent preparation, the color-changing preparation and oxidizing agent preparation advantageously exhibit good free flowability and the increased viscosity of the application mixture is then adjusted once the two components have been mixed. Established polymeric thickeners in cosmetic preparations are cellulose derivatives, such as hydroxyethyl cellulose or xanthan.
Accordingly, at least one object herein is to provide a color-changing agent, by means of which the above cited disadvantages of common color-changing agents are reduced. In particular, at least one object herein is to provide an oxidative color-changing agent for keratinic fibers which is characterized by a very good miscibility of both components: oxidizing agent preparation and color-changing preparation. The thus-resulting application mixture should possess an adequate viscosity, such that firstly the agent can be easily spread, secondly that it remains in place during the application without running out of the fibers.